A bomb shelter on 883 Xietu Road in Huangpu was turned into a wine club, storing 30,000 bottles of red wine; a worker fills up an abandoned shelter with foam concrete to prevent land subsidence and the shelter caving in.
Shanghai has a total of over 700,000 square meters of abandoned bomb shelters honeycombed across the city.
Local government is filling up some of them, while the better preserved shelters are being converted into activity centers, cafes and wine cellars.
Most of the underground shelters were built during the 1960s and 1970s under the admonition of Chairman Mao Zedong to "dig deep and store grain" and also as a defense against foreign invaders.
Most of them are still in good enough condition to offer emergency shelter to citizens, but some have become major safety risks due to severe water percolation and even partial collapse, especially beneath the old residential communities in downtown Huangpu District, according to the district's civil defense office.
Huangpu alone has 582 abandoned civil defense shelters covering 100,000 square meters, or a seventh of the city's total, said Wang Shirui, director with the engineering management department of the office.
"Many of them have been long abandoned and hidden beneath old residential buildings and historic structures. Their entrances and exits have been sealed and that made them difficult to be found," he said.
During the "dig deep" campaign about half a century ago, enthusiastic citizens built a large number of shelters with poor quality bricks, and most of them incorporated no steel beams or concrete due to a shortage of materials in that era, according to Wang.
These often shabby shelters are about 2 meters wide and tall with a vaulted ceiling. After decades of being abandoned, the bricks manufactured in self-built workshops have started to crumble. Since no waterproof materials were used during their construction, most of the shelters have been flooded by underground water and sewage, Wang said.
They have become "time bombs" hidden under the residential houses that could lead to land subsidence and even cause the buildings above them to collapse, he said.
Wang added he was shocked by a cave-in accident that happened in central China last year and became determined to remove the risks to Huangpu once and for all.
In the accident, a female teacher in her 30s was killed in Zhengzhou in Henan Province last August after a large hole suddenly appeared in a road caused by a cave-in of a former bomb shelter beneath.
Flooded underground caves could create other problems such as a damp or stinking environment to families living above. Furthermore, toxic gases such as hydrogen sulphide and marsh gas often accumulate in sealed spaces.
Wang has recently resolved a long nightmare for one household living on Liyuan Road where a shelter cave filled with black water was found under a bedroom.
The district government is using CT technology to search for about 30 such "forgotten" underground shelters. And two dozen have been found, according to Wang.